In sports (especially boxing) fans love to rank the best boxers, players or

In sports (especially boxing) fans love to rank the best boxers, players or teams. So when ranking the Greatest Boxers of All-Time -- is it ethical to include boxers you or anyone else (alive) have never seen before (for no footage exists of them - e.g., Harry Greb)? (Provided that you put in as much research as possible - e.g., books, news archives, boxing historians writings.)

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